(19)
(11) EP 2 072 218 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
21.05.2014 Bulletin 2014/21

(43) Date of publication A2:
24.06.2009 Bulletin 2009/26

(21) Application number: 08169021.6

(22) Date of filing: 13.11.2008
(51) International Patent Classification (IPC): 
B29C 47/50(2006.01)
B29C 47/40(2006.01)
 B29C 47/60(2006.01)
B29B 7/38(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR
Designated Extension States:
AL BA MK RS

(30) Priority: 19.12.2007 JP 2007327383

(71) Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
Kobe-shi, Hyogo 651-8585 (JP)

(72) Inventors:
  • Narukawa, Yutaka
    Takasago-shi Hyogo 676-8670 (JP)
  • Tanaka, Yoshimitsu
    Takasago-shi Hyogo 676-8670 (JP)

(74) Representative: TBK 
Bavariaring 4-6
80336 München
80336 München (DE)

   


(54) Kneading screw and extruder


(57) A kneading screw (1) is disclosed which comprises a screw body (11), the screw body (11) comprising a feed section (9) and a kneading section (10), the feed section (9) comprising screw segments (13) for feeding a to-be-kneaded material to a downstream side and the kneading section (10) comprising kneading segments (19) for kneading the material. The screw body is provided within the kneading section (10) with a multi-stage portion which gradually changes axially in rotating outside diameter. It is preferable that the multi-stage portion be constituted by kneading segments (19) of plural kneading discs different in rotating outside diameter. With such a construction, it is possible to avoid stress concentration on an axial part of the kneading screw (1) and thereby prevent breaking of a spline shaft and abnormal wear of kneading flights.







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Search report